Wheel suspensions for railway cars



Dec. 8, 1959 R. P. HAMMOND WHEEL SUSPENSIONS FOR RAILWAY c'ARs 2Sheets-Sheet 1 Filed Sept. 27, 1957 INVENTOR.

Roland Philip Hummonc BY ATTORNEY Dec. 8, 1959 R. P. HAMMOND 2,915,990

WHEEL SUSPENSIONS FOR RAILWAY CARS Filed Sept. 27, 1957 2 Sheets-Sheet 2Fig. 4

INVENTOR. Roland Philip Hammond ATTORNEY United States Patent WHEELSUSPENSIONS FOR RAILWAY CARS Roland Philip Hammond, Los Alamos, N. Mex.

Application September 27, 1957, Serial No. 686,752

12 Claims. (Cl. 105-216) This invention relates to a railway train andmore particularly to a train of the type known as an articulated train,that is, a train in which the car aisle is substantially continuous,without vestibules, throughout the entire length of the train, and inwhich the train is supported upon wheels positioned at the couplingpoints between the cars throughout the length of the train.

The principal object of the invention is to provide a highly efiicientmeans for mounting the wheels from the cars at the axes of articulationof the train, and to replace the usual mechanical springs with highlyefficient, selfleveling air springs or pneumatic cushioning deviceswhich 'will automatically maintain the train in a preset level planeregardless of variations in loading and regardless oftransversely-acting forces such as wind, centrifugal forces, etc.

Another object of the invention is to incorporate a trackengagingbraking mechanism which will eliminate the usual wheel brakes and theiroperating elements, and which will act to lower the entire train intosimultaneous braking engagement with the tracks throughout its entirelength so as to obtain a maximum braking action with a minimum of stressupon the train structure and to incorporate the braking elements withthe wheel suspension elements so that the latter will serve to bothefficiently and resiliently support the train during normal running, andwhich will serve to apply a braking or retarding action on the trainwhen required.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and efliciency.These will become more apparent from the following description.

In the following detailed description of the invention, reference is hadto the accompanying drawing which forms a part hereof. Like numeralsrefer to like parts in all views of the drawing and throughout thedescription.

In the drawing:

Fig. 1 is a fragmentary plan view of a typical portion of theundercarriage of the improved train;

Fig. 2 is a side view of the portion of the undercarriage of Fig. 1;

Fig. 3 is an enlarged vertical section through one of the air springsemployed in the wheel suspension of the improved train, taken on theline 3--3, Fig. 1;

Fig. 4 is a horizontal cross-section through a compensating valvemechanism, the section being taken on the line 4-4, Fig. 3;

Fig. 5 is an enlarged detail section through a brake shoe as employed inthe improved train, the section being taken on the line 5-5, Fig. 2; and

Fig. 6 is a fragmentary plan view illustrating an alternate method ofmounting wheels upon the improved wheel suspension.

In Figs. 1 and 2 the train car bodies have been eliminated for the sakeof clarity. The bodies may be of desired type or design. They and theirconnecting diaphragms will occupy positions on the undercarriage asindicated by the broken line outlines 10.

The car bodies are supported upon an elongated rec- "ice tangularundercarriage frame 11 preferably, but not necessarily, formed fromstructural channel members having their flanges turned inwardly andsuitably braced such as indicated by the gusset plates 12. A body frame13 of any suitable construction is superimposed and mounted on theundercarriage frame 11 to support the car bodies thereon.

The Wheels of the train, indicated at 14, unitarily mounted on aconventional axle 15, are positioned between the adjacent undercarriageframe 11 of the adjacent cars of the train. The journals of each axle 15extend into suitable journal bearings 16, each of which is mounted inand adjacent to the rear extremity of a tiltable wheel lever beam 17.The wheel lever beams are pivotally mounted upon pivot studs 18 whichare aifixed to, and extend oppositely outward from, each side of theundercarriage frames 11 adjacent the rear of the latter. The pivot studs18 could be welded to the members of the undercarriage frame or could bethe extremities of a pivot shaft extending completely across theundercarriage frame.

The pivot points of the wheel lever beams are positioned in closerrelation to the rear extremities of the lever beams than to the forwardextremities thereof so as to provide a relatively short rear lever armand a relatively long forward lever arm on each wheel lever beam.

The long forward lever arm of each wheel lever beam 17 terminates in apad 19 which rests upon a compressible air spring or sealed accordionlike chamber which will be herein designated as a pneumatic 20. The

pneumatic 20 is supported upon a suitable ledge bracket 7 21 mounted onthe undercarriage frame 11. Air is supplied to the pneumatics 20, aswill be later described, so that the trailing extremity of each car willbe pneumatically supported from the track rails, indicated at 22. Theforward extremity of the undercarriage frame of each car is supportedfrom the rear extremity of the undercarriage frame of the preceding carby means of a coupling device, which forms no part of the presentinvention and which is more completely illustrated and described inapplicants co-pending application, Serial No. 692,860.

Briefly, the coupling device comprises a pivot bracket 23 bolted orotherwise secured at the middle of the trailing extremity of eachundercarriage frame. Each pivot bracket is provided'with a verticalcoupling socket into which a pivot lug 2.4.downwardly extends. Eachpivot lug is formed on or carried by a tongue member 25 afiixed to andextending forwardly from. the middle of the forward extremity of theundercarriage frame of the adjacent following car. Each tongue member 25supports the forward extremity of a car from the pivot bracket 23 of thenext preceding car. Adjacent cars can move horizontally relative to eachother about the axis of the pivot lug 24 which is positionedsubstantially vertically over the axle 15. Thus it can be seen that eachset of wheels 14 supports substantially one-half the weight of apreceding car and one-half the weight of a following car, and that thetotal weight is resiliently biased by the pneumatics 20 through theaction of the wheel lever beams '17. It can be seen that if the weightin the cars increases or the pressure of the air in the pneumatics 20decreases, the undercarriage frames 11 will tend to descend toward therails 22. The tendency to descend is compensated for by automaticallyincreasing the air pressure in the pneumatics, as will be laterdescribed. Advantage is taken of this descending action for applying abraking or retarding action on the train. r

The braking action is accomplished by mounting straight, fiat,renewable, flanged brake shoes 26 under each undercarriage frame beloweach of the pivot studs 18 thereon and directly over the rails 22. Thebrake shoes may be secured to the channel sides of the undercarriageframe in any desired manner, such as by means rails to exert a retardingor braking action on the train.

Air is simultaneously and continuously supplied to all of the pneumatics20 on the train from a trainair line under the control of thelocomfltiv'e engineerl A train line pipe30 leads from the train air lineto each .of .the

wheel mountings ofv the train. The train line pipe 30 supplies air underpressure to the expansible pneumatic 7 20 through atelescopingcompensating valve, designated in its entirety by the numeral 31, whichconsists of an ginverted upper valve cup 32 telescopically fitted over alower valve cup '33. The upper valve cup .32 rests in an'in'vertedretaining socket '34 attached to a bracket arm 35 secured to andextending outwardly from the carriage frame 11. 1 The lower valve cup 33rests in an' annular retaining flange 36 :forrned on a verticallyadjustable platform plate 37 the rear extremity of.which is pivotallymounted for vertical adjustment. As illustrated, the platforni plate ispivoted as shown at 38 upon the forward extremity of one'of the wheellever beams '17 above the wheel lever pad 19 1 thereon. The forwardextremity of the platform plate 37 is adjustably supported upon asuitable adjusting screw 39 which is threaded through the plate intocontact with the pad 19.

, Air is fed from the train line pipe to an air passage 40 in the uppercup 32 by means of a first air tube 41. Air flows from the passage 40,through a valve port 42, controlled by a vertically acting needle valve43, to a valve chamber 44 in the upper cup 32, Air discharges from thevalve chamber 44 through a second air tube 45 leading to a pneumatic airpipe 46 which communicates through the ledge bracket 21 and through thebottom of the pneumatic 20 with the interior of the latter. A bypassreturn pipe 47 is connected between the pneumatic air pipe 46 and thetrain line pipe 30 and a conventional check valve 48 is incorporated inthe return pipe 47 and positioned to prevent air from flowing directlyto the pneumatic from the trainline yet to allow air to flow in thereverse direction. An orifice disc 49 is incorporated in the pneumaticair pipe 46. The disc is provided with a measured bleed orifice 50 whichconstantly bleeds a minimum measured quantity of air from the pneumatic20 to the atmosphere. Thus, when the needle valve 43 is open air canflow from the train line directly into the pneumatics 20 to expand thelatter, and when the valve 43 is closed air will slowly discharge fromthe pneumatics toallow the latter to contract. Therefore, control of thepneumatics resides in the needle valve 43. i

The needle valve 43 is constantly urged toward its seat in the port 42by means of a valve spring 51 which rests upon a spring disc 52 in thelower valve cup 33. The spring 51 acts to resiliently force a valve stem53 against the needle valve 43 to urge the latter to its seat. The disc52 is supported in the lower cup upon a compression disc spring 54 ofgreater compressive resistance than the spring 51.

From the structure thus far described it can be seen that as the wheellever pad 19 descends, the lower valve cup will move downwardly todecrease the compressive force in the spring 51. Eventually a point willbe reached whereythe compression in the valve spring 51 will beins'uficient to retain the valve 42 closed and air will flow by thelatter to prevent further contraction of the pneumatic. Therefore, aslong 'as' there is. air in the train line the pneumatics will maintainthe cars at a predetermined elevation, regardless of changes in :loadconditions in the cars. 7

The predetermined elevation can be'adjusted by adjusting the screw 39 topreloadthe valve spring 51 with any desired compression. Under staticload conditions just sufficient air will pass the valve 43 to compensatefor the loss through the bleed orifice 50 and the cars will remainvertically stationany. V

For brake application services, an annular expansive chamber 55 issuspended in the lower valve cup 33 from a top ring flange 56 fixed inthe top of the cup 33. The expansive chamber 55 is secured to both theflange 56 and the spring disc 52 and has an inherent tendency, when notinflated, to exert a lifting action on the spring disc, assisted bythedisc spring 54. The upward motion of the disc 52 is limited at adefinite position in any desired manner, such as by means of a limitring 58 positioned upon the peripheral portion of the disc 52 so as tocome in contact with the top ring flange 56. The stiffness of the spring54Vis chosen so that a pressure of air suflicient in the. pneumatics tolift a fully loaded car is 'insuflicient in the annular expansivechamber 55 to move. it downward away from its compressed position orstop. The expansive chamber 55 is, however, normally inflated at trainline pressure, substantially higher than the pres spring 54. Theposition assumed will be lowerat higher train line pressures, andvice-versa.

As long as the train line pressure remains the compression of the spring54. However, a reduction in the train line pressure will allow all ofthe spring discs on the train to move upwardly to increase thecompression in the valve springs 51 so that the wheel lever beams 17 andtheir pads 19 may move further downward without opening the valves 43and thus establish a different controlled position for the lever beams.Sufficient reduction of train line pressure in this way will establish acontrol position for the lever beams such that the brake shoes 26contact the rail 22, providing a mild braking action. Stillfurther'reduction in train line pressure can increase the braking actionto any extent desired, since still further lowering of the controlposition of the beams will be attained only after the escape of airthrough the orifice 50 has lowered the pressure in the pneumatics toless than that which can fully support the weight of the car or truck.Thus, the weight of the car or truck becomes divided between the wheels14 and the brake shoes 26, and the degree of such division, and hencethe amount of braking eifort, is controllable by adjusting the pressurein the train air line.

It is clear from the foregoing that in such a brake application, calleda service application, the air pressure in the train line is alwayshigher than in the pneumatics, so that the check valves 48 remainclosed. For an emergency brake application, however, the train airlineis completely vented to the atmosphere When this is done, the pressurein the supply pipes 3il-soonfalls below that in the pneumatics 2th, andthe check valves 43 will be forced open by the pressure differential toinstantly reduce the pressure in the pneumatics essentially atatmospheric pressure. i K j Thus, all of thepneumatics instantly andsimultaneously contract to allow the brake, shoes to descend intofrictional engagement with the rails for train retardation purposes. Thebrake shoes can be released by simply returning thetrain line pressureto the normal running pressure. The increase in pressure in thetrainline closes the ,check valves 48 and returns all .of the springdiscs 52 to their preset compensating position, through expansion of theexpansive chambers 55 to their running position.

Thus, it can be seen that'all of the compensating valves 31 can bepreset in any desiredmanner, such as by reguuniform, the spring discwill remain vertically stationary against the bias of the contractingtendency of the chamber 55 and lating the adjusting screws 39 to levelthe entire train at a glven distance above the tracks, and that thislevel will be automatically maintained, regardless of variations inloading and regardless of the centrifugal tendency of the cars to tiltwhen rounding curves at high speeds.

It can also be seen that by the operation of a simple three-way valve inthe locomotive, the entire train can be lowered to exert a controlledand uniform braking act on on the rails throughout the entire length ofthe tram so that no strains are imposed upon draw bars, cars, andcouplings.

The only elements which might require servicing are the compensatingvalves 31. The latter are unattached, other than by the air tubes 41 and45, and can be quickly lifted from the retaining flanges 36 and droppedfrom the sockets 34 for quick replacement at junction points While thetrain is in transit.

The platform plate 37 could, if desired, be positioned at any pointalong the lever beam 17 between the pivot stud 18 and the pad 19,without aifecting the above described action of the compensating valve.The degree of movement will, of course, diminish as the pivot stud isapproached.

The invention has been described in connection with a conventional wheeland axle unit. It is conceivable that the axle could be omitted andsingle independent wheels used, as illustrated in the alternate form ofFig. 6. In the latter form, wheel lever beams 59 are employedcorresponding in operation to the wheel lever beams 17 previouslydescribed. The rear extremity of each of the wheel lever beams 59,however, are bifurcated, as shown at 60, and suitably journalled toreceive independent track-engaging wheels 61, thus eliminating theunitary axle 15 of the previous form, if so desired. The other elementsof the suspension remain as previously described.

While the improved wheel suspension has been described as applied to oneextremity of a car of an articulated train, it could, of course, beapplied to both extremities of a conventional car, or to a wheeled,car-supporting truck, or other wheeled vehicle, all of which are hereinincluded by the term car.

While a specific form of the improvement has been described andillustrated herein, it is to be understood that the same may be varied,within the scope of the appended claims, without departing from thespirit of the invention.

Having thus described the invention, what is claimed and desired securedby Letters Patent is:

1. A wheel suspension for a railway car comprising: alongitudinally-extending wheel lever beam at each side of said car; atrack-engaging wheel rotatably mounted at the first extremity of eachlever beam and supporting the latter from a track rail; pneumatic meanssupporting the second extremity of each lever beam from said car; meansfor applying weight from said car to said lever beams between saidwheels and said pneumatic means; and means for supplying compressed airto said pneumatic means.

2. A wheel suspension for a railway car as described in claim 1 havingmeans for increasing the pressure of air in said pneumatic means inproportion to an increase in weight applied by said weight-applyingmeans.

3. A wheel suspension for a railway car as described in claim 2 having abrake shoe afiixed to said car over said rail and means for dischargingair from said pneumatic means to allow said car to descend to bring saidshoe into frictional engagement with said rail.

4. A wheel suspension for a railway car comprising: alongitudinally-extending wheel lever beam at each side of said car; atrack-engaging wheel rotatably mounted at the first extremity of eachlever beam and supporting the latter from a track rail; pneumatic meanssupporting the second extremity of each lever beam from said car; meansfor applying weight from said car to said lever beams between saidwheels and said pneumatic means; a compressed air line communicatingbetween the two pneumatic means; supply means for supplying compressedair to said air line; an independent valve controlling the flow of airfrom said air line to each pneumatic means; means operable from verticalmovements of the second extremity of each lever beam for actuating saidvalve to supply compressed air to the pneumatic means at that extremity;and means for discharging air from each pneumatic means.

5. A wheel suspension for a railway car as described in claim 4 in whichthe means for actuating said valve comprises: a valve stem arranged tomove said valve against the pressure of said air and to a closedposition; a valve spring acting against said stem to urge said valve tothe closed position; and means supporting said spring from the secondextremity of said wheel lever beam so that upward and downward movementsof said second extremity will increase and decrease, respectively, thereaction of said spring on said valve.

6. A wheel suspension for a railway car as described in claim 5 having ableed orifice continually discharging air from each pneumatic means.

7. A wheel suspension for a'railway car as described in claim 6 having aby-pass conduit communicating between said compressed air line and saidsupply means, and a check valve in said by-pass conduit positioned toprevent air from flowing from said supply means to said pneumatic meansyet allowing air to flow from said pneumatic means to said supply meanswhen the pressure in the latter drops below the pressure in the formerso as to allow said car to descend toward said rail; and a brake shoefixedly mounted on said car so as to frictionally engage said rail inconsequence of the descent of said car for braking purposes.

8. A wheel suspension for a railway car as described in claim 7 havingmeans for increasing the reaction of said valve spring when the airpressure in the supply means falls below a predetermined pressure so asto maintain said valve closed during a longer are of travel of saidsecond extremity.

9. A wheel suspension for a railway car as described in claim 8 havingmeans for manually adjusting and presetting the reaction of said valvespring.

10. In a wheel suspension for a railway car of the type having anexpansible pneumatic resiliently supporting said car on a wheeled,rail-engaging, car body supporting structure so that expansion andcontraction of said pneumatic 'will respectively raise and lower saidcar, means for controlling a supply of compressed air to said pneumaticcomprising: an air supply pipe communicating with said pneumatic; acompensating valve positioned in and controlling the flow through saidsupply pipe; means for actuating said compensating valve in consequenceof the expansion and contraction of said pneumatic; and means fordelaying the opening of said valve when the pressure in said supply pipedrops below apredetermined pressure.

11. Means for controlling a supply of compressed air to a pneumatic asdescribed in claim 10 having a check valve arranged to open when thepressure in the pneumatic exceeds the pressure in said supply to returnair from the former to the latter.

12. Means for controlling a supply of compressed air to a pneumatic asdescribed in claim 11 having a bleed orifice continuously dischargingair from said pneumatic to the atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS999,424 Young Aug. 1, 1911 1,604,564 Cecero Oct. 26, 1926 2,605,718 Omaret al. Aug. 5, 1952 2,606,505 MacVeigh Aug. 12, 1952 2,648,546Falkenhagen Aug. 11, 1953 2,841,410 .Kessler et al. July 1, 1958

